Series flash device



May 13, 1969 I K. HERRMANN ,875

SERIES FLASH DEVICE Filed 001;. 4. 1966 J 714 7b l/Tc 5 FIG'A spams CONDUCTOR PASTED PROXIMATE THE LAMP AND RELEASED upon FLASHING OF THE LAMP I00) 7b IOC HEAT DEFORMABLE PLASTIC STRIP MASS CONDUCTIVE UPON FUSION FIGJB.

FIG. 2.

wmvesses iNVENTOR I Karl Herrmon n Y my; 0 2A m ATTORNEY United States Patent olace 3,443,875 Patented May 13, 1969 Int. Cl. F21]: 5/02 US. Cl. 431-95 1 Claim ABSTRACT OF THE DISCLOSURE A disposable photoflash combination which provides automatic switching and allows series ignition of the lamps. The simple non-repeatable series switching mechanism associated with the lamps is activated by the heat generated upon flashing a lamp to connect the subsequent lamp to the ignition circuit.

This invention relates to a flash device for photo graphic purposes for several photoflash lamps which may be flashed one after the other, individually or in groups. It is already known, as shown in German Gebrauchsmuster No. 1,838,585, to arrange a mechanical switch on a flash device by means of which the contacts of the photoflash lamps are connected one after the other across a release switch to an igniting current source. Such a mechanical switch must, however, be switched-on by hand after each flashing. It is also known, as shown in German Patent No. 848,012, to use a switch mechanism in a series flash device in which in parallel with the photoflash lamps an electromagnet is connected to the current source, and is always excited when a lamp is flashed, whereby a step-by-step switch is actuated to which energy for switching-on is supplied by stored mechanical energy. In this latter case, switching-on takes place automatically after each flashing of a photoflash lamp, but the energy for actuating the electromagnet is taken from a battery of the flash device, the life of which is thereby much reduced.

For overcoming these drawbacks, in German DAS 1,192,047 there is shown a series flash device for automatic switching-on in which with each single photoflash lamp a bimetal member is associated which is heated-up through the heat brought about in flashing a photoflash lamp and which releases a switching reaction. This method requires, however, a special flash device loaded with individual lamps or with a lamp magazine. It is, for different reasons, quite advantageous to use photoflash lamps in the form of throw-away packs consisting of inserts which contain several lamps and have a reflector for each single lamp. Flash devices loaded with such inserts consist substantially only of a support for the insert and of a current source. The support and current source may also be constituents of the camera. It has also already been proposed to couple the switching-on in such an insert with the film pull-down of the camera or wlth its shutter, respectively. Such devices, however, have the disadvantage that special attachments have to be provided on the camera.

It is, therefore, an object of the present invention to provide a device for automatic switching-on a series flash device which may be used with any desired camera.

It is another object of the invention to provide such a device which may be used for a so-called throw-away pack in which the lamps and the pack serve as a flashing insert formed as a unit.

A series flash device containing several photoflash lamps in which the current inleads of each lamp are to be connected one after the other, individually or groupwise, across a release switch to the ignition circuit, is according to the invention characterized in that on the lamps themselves, or on a throw-away pack associated with the latter, such means are provided which connect automatically the current inleads of the next lamp in a non-repeatable switching action to the ignition circuit in consequence of the combustion process taking place after ignition of the lamp. Since the switching process cannot be repeated, the switching means are simple and not susceptible to troubles.

In, accomplishing this invention, different approaches have been taken. There is provided on the lamps, or on the throw-away pack, such switching means which are actuated through the heating brought about when a lamp is flashed.

In one embodiment of the invention, one of the two current inle'ads of each photoflash lamp is connected With a common first conductor belonging to the ignition circuit. The second conductor completing the ignition circuit is connected only with the second current inlead of the first photoflash lamp. The second current inleads of the other photoflash lamps are made as weakly resilient contact bands or they are each connected with such a band. The resilient contact band is held fast, under a stress, to the preceding photoflash lamp, or at a place near this lam and the securing means is designed in such a manner that it disconnects in consequence of the heating brought about when a preceding lamp is flashed and the prestressed contact band then contacts the second conductor of the ignition circuit.

In another embodiment, again one of the two current inleads of each photoflash lamp connects to a common first conductor of the ignition circuit. On each photoflash lamp there is provided a current bridge to which the second current inlead of the next lamp is carried, but which bridge is not in electrical contact with the second inlead. This latter contact is made only when a lamp is flashed.

The invention will now be explained by way of the accompanying figures.

FIG. 1A shows an example of an embodiment of the invention which utilizes resilient contact elements.

FIG. 1B shows an alternative construction for the embodiment shown in FIG. 1A.

FIG. 2 shows another example of an embodiment which utilizes current bridges.

As shown in FIG. 1A several photoflash lamps 1, 1a, 1b, and 1c are arranged in a throw-away pack which is represented by the reflectors 2, 2a, 2b, and 21: associated with the individual lamps. One current inlead 3 of all the photoflash lamps is connected to a common conductor 4. There is initially connected to the second conductor 5, only the first photoflash lamp 1 with its current inlead 6. The succeeding lamps have resilient contact bands 7a, 7b, and 7c, which are initially pasted with initial stress to the preceding flashlamp. The first photoflash lamp 1 has been previously flashed, and adhesion of the contact band 7a has been released. Thus the contact band 7a abuts on conductor 5 in consequence of its bending elastically. The conductors 4 and 5, together with battery 8 and re lease switch 9 constitute the ignition circuit. Upon the next closing of switch 9 the lamp 1a is ignited, and the adhesion of contact band 7b is released by the combustion.

FIG. 1b shows another example of an embodiment of the invention. The contact bands 7b and 7c are maintained in stressed condition by thin plastic strips 10a and which are attached near the lamp to the throw-away pack. The lamp 1 has already been flashed and has, thereby heated up strip 10 so much that it softened and was bent by the stressed spring 7a so that the spring 7a now abuts on conductor 5.

In the embodiment shown in FIG. 2 there is sealed in every photoflas'h lamp 11 a small metal tube 12 closed at its lower end. All the small tubes 12 are connected with one pole of the ignition circuit source, and a current inlead 13 of all the lamps 11 is connected with the other pole of the ignition current source. The other current inlead 14 of the first lamp is connected with that pole of the ignition current source to which the small tubes 12 are also connected. Each of the individual lamps includes an incandescent filament which connects to the current inleads. The other current inleads 14a and 14b of the remaining lamps are carried to pins 15 projecting into the small tubes 12. The intermediate space is filled with a mass 16 serving as the current bridge, and acting first as an insulator between the small tube 12 and pin 15. Where a lamp is flashed 011, mass 16 in the small tube of this lamp melts and brings about connection of the next lamp to the ignition circuit. A current bridge mass 16 as is used in well-known electric Christmas candle lamps has proved effective as the mass 16. Each current bridge comprises two contact members, the tube 12, the pin 15 and the mass 16. Flashing of the lamp renders the mass 16 conducting to complete the circuit.

What is claimed is:

1. A disposable multiple photoflash lamp combination comprising:

(a) a unitary body comprising a plurality of photoflash lamps adapted to be flashed in a predetermined sequence;

(b) a pair of current inleads associated with each of said lamps and connecting to current-responsive ignition means within each said lamp for initiating the flashing of each said lamp;

(c) one current inlead of each of said pairs of lamp inleads being connected to a common bus conductor which is adapted to be connected to one pole of a source of electrical energy for flashing the lamps;

(d) one of said lamps constituting the initial lamp to be flashed, the other current inlead of said initial lamp to be flashed being in direct contact with another bus conductor adapted to be connected to the other pole of said electrical energy source;

(e) a plurality of single action nonrepetitive switching means each comprising an individual spring conductor directly pasted onto the envelope of the photo flash lamp which is immediately preceding in said predetermined flashing sequence, each said spring conductor being retained under stress in contact with said envelope by the adhesive paste which softens whenv heated;

(f) the remainder of said other inleads of each of said succeeding lamps in said predetermined flashing sequence connected to the said spring conductor which is pasted to the envelope of the immediately preced ing lamp in said predetermined flashing sequence;

(g) flashing of said initial lamp in said flashing sequence heating said adhesive paste by conduction throughlsaid envelope upon flashing of said lamp, said adhesive paste when softened releasing said spring conductor to complete electrical continuity between said other current inlead of the immediately following lamp in said predetermined flashing sequence and said other bus conductor; and

(h) similarly, for the other lamps in said combination, the flashing of the immediately preceding lamp in said predetermined flashing sequence eifecting electrical continuity between said other bus conductor and said other. current inlead of the lamp immediately following in said predetermined flashing sequence.

References Cited UNITED STATES PATENTS 2,725,821 12/ 1955 Coleman. 2,863,021 1'2/ 1958 Green 200-126 X 3,026,392 "3/1-962 Lovret 200-142 X 1,284,877 11/1918 Connor et a1. 15842.4 X 1,958,081 5/1934 Denison 158-28 X 2,674,241 4/ 1954 Freedman 158-42.4 X

FOREIGN PATENTS 1,192,047 4/ 1965 Germany.

JAMES W. WESTHAVER, Primary Examiner.

US. Cl. X.R. l1.5; 2401.3 

